Factors affecting beeswax emulsion properties and stability | |
| Author | Yada Lekdumrongsak |
| Call Number | AIT Thesis no.FB-05-04 |
| Subject(s) | Beeswax Emulsions |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. FB-05-04 |
| Abstract | Beeswax emulsion was formulated by phase inversion technique at the phase volume ratio of 0.74, hydrophile-lipophile balance 12, all single emulsifier systems of the saturated C18 with a heterocyclic sorbitol end of an oil-in-water emulsifier, Tween60, at 10, 20 and 30% of wax content resulted in the incomplete, nonhomogeneous suspensions. These non-emulsified products also appeared in the mixed of an oil-in-water (Tween60)/ water-in-oil (Span60) system at 10% but partially emulsified and completely homogeneous, stable in the mixed systems was observed at 20 and 30% Tween60/ Span60, respectively. Of the six different structures of mixed emulsifying agents at three dosage levels were studied at the three phase volume ratios. For an effect of the types of emulsifying agents, the mixed of Tween/Span series at 30% of wax with the different fatty acid length of C12, C16, C18, the C18,0 of saturated and C18,1 of unsaturated fatty acid, an aliphatic configuration of Myrj and Tween with one heterocyclic ring, also the different polyoxyethylene of Myrj were investigated. These exhibited that emulsifier structure had great effect on both emulsion properties and stability. The longer C-chain of emulsifiers resulted in small internal droplet, thin, stable emulsion, an unsaturated or aliphatic end of the structure could induced product destability but not affected to the size of the wax particles and viscosity of emulsion. In contrary to the larger number of polyoxyethylene group in the emulsifier structure which generated a high viscosity, larger emulsion droplets but almost did not has any affects on the product stability. In terms of the emulsifier concentration, the Tween60/Span60, the most stable system from the study for the emulsifier type, was evaluated at 20, 30 and 40%. Emulsifier concentration that increased from 20 to 30% gave smaller particles, thinner and dramatically increased in stable emulsion. As the concentration increased further from 30 to 40%, only a little change had been found. In addition, phase volume ratio also influenced the emulsion properties. At the phase volume ratio of 0.64, 0.74 and 0.84, it was observed that the greater percent of wax in formulation indicated the higher viscosity and a little better stability. The application of fniit coating was conducted to investigate the changes of qualities compare with the commercial shellac. The 26% and 18% beeswax emulsion were applied to the tangerines comparing the changed of qualities to the commercial shellaced fruits and unwaxed fruits. The different water loss reduction of beeswax coating was undetectable in the fruits at ambient storage, but the loss reduction was significant superior over the nonwaxed fruits approximately 19% at cooling storage. After 2ldays storage at 4+/-2°C, nonwaxed tangerines lost their weight at 12.60% whereas the 26% and 18%beeswax coating fruits lost 10.15% and 10.19% and shellaced treatment lost at 7.66% of their fresh weight. Color measurement indicated that the coated samples, either beeswaxed emulsion or commercial shellaced fruits, exhibited degreening deduction. The changing of a/b ratio from initial, on top of fruits, was 0.37 after 7days at ambient and 0.12 after 21 days at cooling storage condition while the smaller values of change were observed in beeswax and shellac coating fruits. The a/b reading after 7days at ambient of 26%beeswax, 18%beeswax and 18%shellac coating fruits were differed from initial at 0.28, 0.31 and 0.26 and the alteration after 2ldays at cooling storage were only 0.07, 0.08 and 0.10, respectively. This color change was also perceived by consumer in the refrigerated fruits but was not detected in ambient storage fruits. The investigation on respiration rate showed all wax coating could reduce fruit respiration. This was obviously seen at 2hrs immediately after coating. At ambient, the 26%beeswax, the 18%beeswax and the 18%shellac coating fruits respired at lower rate of 15.9, 17.3, 17.7 m1CO2/kg.hr compared to the unwaxed fruits at 21.6 m1CO2/kg.hr. At cooling, the 26%beeswax, the 18%beeswax and the 18%shellac coating fruits respired at only 5.2, 4.4 and 4.8 mlCO2/kg.hr compared to the unwaxed fruits at 7.5 mlCO2/kg.hr. Beeswax emulsion was superior over the commercial shellac emulsion in terms of the fruit flavour before peeling and consumer perception. The overall preference of the commercial shellaced tangerines after 21 days storage at cooling temperature was higher but panelists' preference was changed after the coated materials had been informed. An average preference score of shellaced fruits decreased from 7.0 to be 5.5 but no significant reduction found on beeswaxed fruits. |
| Year | 2005 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. FB-05-04 |
| Type | Thesis |
| School | School of Environment, Resources, and Development |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Food Engineering and Bioprocess Technology (FB) |
| Chairperson(s) | Athapol Noomhorm; |
| Examination Committee(s) | Jindal, Vinod Kumar;Rakshit, Sudip Kumar; |
| Scholarship Donor(s) | Royal Thai Government Fellowship; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2005 |